Bund Testing

A bund is defined as a secondary containment facility designed to prevent leaking contents from contaminating the environment. In order to comply fully with the requirements of the Water Pollution Act 1997, 1990 it is imperative that bund integrity is tested on a regular basis.

A bund must be structurally strong enough to withhold the pressures exerted if it had to contain the full contents of the primary tank plus a factor of 10% volume (initially designated volume factor to recognise the presence of rainfall in external bunded areas). A bund must also be impervious to the liquid stored in the tank and to water, as this is the test medium used.

The standard protocols that apply to bund tests:

Bunds should be tested at least every three years. However, it is recommended to test more frequently in certain cases such as highly sensitive environmental areas.

The testing period is gauged when bunds are filled to the minimum capacity and monitored for loss after a 6 hour, 24 hour or 5 day test period.

The bund must be constructed of a compatible material capable of containing the liquid being stored. A common error found in the industry is storing corrosive liquids in a steel bund which is highly likely to corrode and leak over time

Bulk tanks for storing fuel, oil and chemicals often pose the greatest spillage risk on site. The Control of Pollution (Oil Storage) Regulations 2001 requires sound tanks and bunding of 110% of the capacity of the bulk tank to contain a spill should it occur.